AK-47 rifles are so-called gas powered firearms, in which the discharge gases from a fired round of ammunition serve to automatically eject the spent cartridge casing from the just fired round and to chamber a new round for firing. The standard charging mechanism of an AK-47 is fairly straightforward. These firearms comprise a barrel in communication with a firing chamber, or breach, and a bolt used to provide access to the breach. The barrel comprises a port or similar aperture which permits some of the discharge gases created from the firing of a round of ammunition to escape the barrel through the port. The port is in communication with an adjacent chamber known as a gas block, which in turn is in communication with an adjacent, substantially cylindrical structure known as a gas tube. Contained within the gas tube is a piston known as an operating rod. The operating rod has a forward portion with an outside diameter substantially the same as the inside diameter of the gas tube. The rearward end of the operating rod is in connection with the bolt assembly. The operating rod is designed to move forward and rearward within the gas tube, with its rearward movement designed to simultaneously force the bolt assembly rearward, which in turn compresses a recoil spring mechanism. The recoil spring mechanism in turn forces the bolt assembly forward, returning it to its firing position, which in turn moves the operating rod forward within the gas tube.
A standard AK-47 must be charged in order to operate. Charging of the firearm comprises the loading and reloading of ammunition into the firing chamber and occurs during the rearward and forward movement of the bolt assembly described above. During operation, charging is done automatically by utilizing the discharge gases of a fired round of ammunition. When a round is fired, the cartridge casing remains at one end of the barrel and the gases formed by the explosion force the bullet to travel down the length of the barrel. As the bullet passes the barrel port, some of the discharge gases escape through the barrel port and pass through the gas block into the gas tube, where the gases impinge upon the forward portion of the operating rod, driving it rearward. This rearward travel of the operating rod moves the bolt rearward, opening the breach, ejecting the spent cartridge casing from the breach, and compressing the recoil spring mechanism in connection with the rear portion of the bolt. While the bolt is thus in its rearward position and the breach is opened, a new round may be loaded into the breach by action of a spring mechanism in an ammunition magazine. The bolt is returned to its forward position by the recoil spring mechanism, closing the breach and returning the operating rod to its forward position. This process may continue until all of the ammunition is used and the ammunition magazine and the firing chamber are both emptied.
The automatic loading cycle of each round of ammunition described above takes place upon the firing of the previous round. However, the initial charging of the firearm in which the first round is loaded into the firing chamber must be accomplished manually, as no discharge gases have yet been created to accomplish this task. Initial charging of a standard AK-47 is accomplished by manually drawing the bolt assembly rearward. This is done by manually grasping and drawing back a charging handle which is in connection with the bolt assembly and located on the right side of the firearm. Drawing the charging handle rearward results in the same loading of the round into the breach by the spring mechanism in the ammunition magazine as described above. Releasing the charging handle allows the recoil spring mechanism to return the bolt to its forward position, closing the breach, resulting in the firearm being loaded and ready for firing.
The current state of the art for initially charging an AK-47 is less than ideal. A standard AK-47 presents a training problem for the operator. One significant issue is the charging handle being on the right side of the firearm. A right handed operator will hold the pistol grip of the firearm in the right hand and support the barrel of the firearm with the left hand. The butt of the rifle is kept on the operator's right shoulder and the right hand remains on the pistol grip at all times, for safety, leaving the left hand to manually charge the firearm. In order to manually charge the firearm the left hand must be removed from the barrel and the operator then reaches over or under the firearm to grasp the charging handle with the left hand. The use of the left hand in the described manner usually results in the loss of sight picture and an unbalanced firearm because of the transition of the operator's hand over or under the firearm. When shooting the firearm the left hand supports the barrel of the firearm and keeps it steady. Upon removal of the left hand the barrel tends to dip downward and sight picture to the target is lost. Since the charging handle is located near the rear of the firearm on a standard AK-47, the requirement of the operator to reach back also jeopardizes the firearm balance, introducing lateral movement when charging the firearm. This method of charging also results in slower charging due to the amount of distance the left hand must travel.
Another deficiency of the charging mechanism of the standard AK-47 rifle is that the gas tube of the standard AK-47 rifle has a closed cylindrical configuration. It has no opening to allow for easy access to its interior for purposes of cleaning or allowing air flow to cool the firearm. The greatest amount of debris and fouling occurs within the gas block and the interior of the gas tube, since the discharge gases contain spent powder residue. This residue stays in the gas tube and tends to build up as round after round is fired. If it is not periodically removed the charging mechanism of the firearm will fail to operate properly, resulting in improper or even unsafe operation. In order to clean this residue the firearm must be disassembled so that a cleaning cloth can be inserted into the gas tube. This is a time consuming operation and requires frequent periods of inactivity of use of the firearm. Moreover, the closed configuration of the gas tube prevents easy visual inspection of the firing chamber; that is, one cannot visually inspect the chamber to determine whether cleaning is needed or even if a round is loaded therein without some degree of disassembly of the firearm. This presents a safety issue.
Another deficiency of the charging mechanism of the standard AK-47 rifle is that the bolt assembly has no bolt locking mechanism. That is, the bolt is always positioned forward pressing against the firing chamber as a result of the recoil spring mechanism, and there is no way to keep it away from the firing chamber unless the operator applies a constant force on the bolt assembly by drawing and holding back the charging handle. Upon the operator releasing the charging handle the bolt assembly returns to the forward position by the recoil spring mechanism.
The standard AK-47 rifle has a safety lever located on the right side of the firearm near the charging handle. When the safety lever is engaged the trigger is locked and cannot move. The safety lever is so positioned as to block the travel of the charging handle when the safety lever is in the locked position. This means that the charging handle cannot be fully drawn rearward to retract the bolt assembly in order to chamber a round when the trigger is locked and the safety lever is engaged. In order to charge the firearm the safety lever must be disengaged, resulting in the trigger not being locked during charging. This presents another potential safety issue.
The basic design of the AK-47 rifle described above also pertains to other popular gas powered firearms, such as the various Kalashnikov variants (AK-74, AK-101, AK-103, and others), the Samozaryadniy Karabin sistemi Simonova (SKS) rifle and its variants, and the Fusil Automatique Leger-Light Automatic Rifle (FN-FAL) and its variants, as well as other designs. In this respect, to the extent the deficiencies described above also apply to these other gas powered firearms, the remediation which is addressed by the present invention applies to these firearms as well.
There thus remains a need for an improved charging mechanism for a gas powered firearm that is easier to use for right handed operators, improves the safety profile of the firearm, is easier to clean, and is simple and cost effective to manufacture and to retrofit into existing firearms.
It is therefore an object of an aspect of the invention to provide an improved charging mechanism for a gas powered firearm which adds safety features to the firearm.
It is a further object of an aspect of the invention to provide an improved charging mechanism for a gas powered firearm which is easier to use for right handed operators.
It is yet a further object of an aspect of the invention to provide an improved charging mechanism for a gas powered firearm that is easy to clean and maintain.
It is yet a further object of an aspect of the invention to provide an improved charging mechanism for a gas powered firearm which is easy to manufacture.
It is yet a further object of an aspect of the invention to provide an improved charging mechanism for a gas powered firearm which is easy to retrofit to an existing firearm.
It is yet a further object of an aspect of the invention to provide an improved charging mechanism for a gas powered firearm which allows for faster loading and more accurate operation of the firearm.
It is yet a further object of an aspect of the invention to provide an improved charging mechanism for a gas powered firearm that improves the durability of the firearm by reducing harmful heat buildup.
It is yet a further object of an aspect of the invention to provide a method for retrofitting a gas powered firearm with an improved charging mechanism.
Other objects of this invention will be apparent to those skilled in the art from the description and claims which follow.